Get tax year from date

I have a Date column. Here in the UK the tax year runs from 6th April - 5th April so the Tax year 6th April 2019 - 5th April 2020 might be referenced to as the 2019/20 tax year.

I would like to be able to add a column Tax Year which writes values like "2019/20" or "2019/2020" based on Date, how can I do this?